Pfizer's bivalent meningococcal B vaccine targeting factor H-binding protein (MenB-FHbp, Trumenba) elicits bactericidal responses against diverse meningococcal B strains after the second and third doses in adolescents and young adults, according to two phase 3 studies published online in The New England Journal of Medicine.

Meningococcal B makes up a large proportion of invasive meningococcal disease in the U.S., Europe, and other regions, the authors note in their article.

Neisseria meningitidis causes invasive meningococcal disease, which occurs predominantly in infants, adolescents, and young adults. Patients frequently present with symptoms similar to those of meningitis or septicemia. Death occurs in up to 15% of infected persons, and up to 20% of survivors have long-term impairments,” reported Dr. Lars Ostergaard from Aarhus University Hospital.

In 2014, MenB-FHbp became the first meningococcal B vaccine approved by the FDA. The Centers for Disease Control and Prevention currently recommends meningococcal B vaccination for at-risk individuals age ten years or older and for vaccination to be considered in those ages 16 to 23.

To assess the safety and immunogenicity of the vaccine, Dr. Ostergarrd et al. randomly allocated 3,596 adolescents (ages 10 to 18) to receive either MenB-FHbp or hepatitis A virus vaccine and saline – and 3,304 young adults (ages 18 to 25) to receive MenB-FHbp or saline – at baseline, two months and six months.

In the modified intent-to-treat population, human complement serum bactericidal activity (hSBA) titers rose by a factor of four or more against the four primary test strains of meningococcal B in 56% to 85% of adolescents after two doses of MenB-FHbp, and from 79% to 90% of adolescents after three doses.

The percentages of young adults ranged from 55% to 86% and 79% to 90%, after the second and third doses, respectively.

“Responses to the four primary strains were predictive of responses to the ten additional strains,” the researchers report. The MenB-FHbp vaccine was associated with mild or moderate pain at the injection site in most recipients.

“Broadly protective hSBA responses were observed in both of these phases 3 trials after three doses of MenB-FHbp . . . and primary immunogenicity endpoints were met,” the researchers report.

Immune responses were also reported after the first and second doses. These results are consistent with those from phase 2 licensure trials,” they conclude.

The study was supported by Pfizer, which makes the Trumenba vaccine. Several of the authors have disclosed relationships with the company.